"""
	使用函数来实现一个计算器
"""

def add(num1,num2):
    return num1 + num2

def sub(num1,num2):
    return num1 - num2

def mul(num1,num2):
    return num1 * num2
     
def div(num1,num2):
    return num1 / num2
    
    
num1 = int(input("Enter Numer One"))
num2 = int(input("Enter Numer Two"))
operator = input("1.+ 2.- 3.* 4./")

if operator == "1":
    print(add(num1,num2))
elif operator == "2":
    print(sub(num1,num2))
elif operator == "3":
    print(mul(num1,num2))
elif operator == "4":
    print(div(num1,num2))
